Improvement in thill-couplings



D. A. JOHNSON Thin-Coupling.

No.r98,803. Patented Jaw-1, 1878.

UNITED STATES PATENT OEEIoE.

DANIEL A. JOHNSON, OF BOSTON, MASSACHUSETTS.

IMPROVEMENT IN THlLL-COUPLINGS.

Specification forming part of Letters Patent No. 198,803, dated January '1, 1878; application filed october 18,1877.

To all whom it may concern:

Be it known that I, DANIEL A. JOHNSON, of Boston, in the county of Suffolk and State of Massachusetts, have invented an Improved (Phill-Coupling, of which the following is a specication:

l Figure 1 represents myimproved thill-coupling in side elevation; Fig. 2, a cross-section, 1 the conning-bolt being shown in elevation;

and Fig. 3, a top view thereof.

In the drawing, the Xed disk a projects from the bar b, to be connected, as usual with the axle by means of an axleclip, c, as s own in dotted lines.

The movable disk c has a projecting portion, d, adapted to be attached, in any usual manner, to the thills. The face of the disk et is shown as provided with an annularly-projecting rib, 2, to iit an annular cavity, 3, made in the disk c. The shape of the 4projection and cavity may be varied from that shown in Fig. 2 without departing from this invention, so long as the projection on one ts a concavity in the other and the parts are so shaped and Iitted together as to follow up the abrasive wear between them.

It is obvious that it is immaterial which disk is provided with the projection and which 'with the concavity. I prefer to place between the disks a washer Orwe'arin g-plate, f, of metal, leather, or other suitable material commonly used for washers.

The bolt g is made round at 4, where it fits the movable disk connected with the thill, and square, or of other irregular shape, as at 5, where it fits the stationary or iixed disk, or vice versa, so that such bolt cannot turn and become detached from the nut which holds the bolt, or vice versa, by the action of the thills. 1

Instead of making this bolt square, as describedyI may place a friction-plate, h, be-

tween the bolt-head and the movable disk, and a tail-piece, i, of the plate may tit a notch, j, in the iron b to retain the plate stationary,

therebypermitting the bolt-head to rest against a stationary rather than against a moving surface. This bolt, passed through the two disks, j

is provided with a spring, k, one end of which bears against one of the disks, while the position ot' the other end is governed by a nut ,fitted to the screw-threaded portion of the bolt.

In vthe drawings this spring is contained within a sleeve, Z, the end of which is iscrewthreaded, to fit the threads of thebolt'f' This spring, held in this `way, acts""to press the movable towardtheAiXed/"disk, and to 'keep them together, so that all wear will be compensated for, and that the coupling will notV rattle.

Instead of making the sleeve serve the purpose of the nut, it is obvious that the same result would be gained by permitting the sleeve to move freely over the bolt, under the action of a nut, m, as shown in dotted lines.

Two disks held together, as herein described, by abolt and spring provided with ears, as common with whifetree-plates, may be employed to retain the whiffletree snugly in posig, extended through such disks, and provided with the portions 4,5, the spring, and a nut to operate all, substantially as described.

In testimony whereof I have Signed my name to this specification in the presence of two subscribing witnesses.

DANIEL A. JOHNSON.

Witnesses:

Gr. W. GREGORY, S. B. KIDDER. 

